Automatic ignition unit for gas burners



Jan. 10, 1956 R. L. PERL AUTOMATIC IGNITION UNIT FOR GAS BURNERS 2 Sheets-Sheet 1 Filed Nov. 20 1950 fl l l l l UH' NI H P I 3 m W WA Jan. 10, 1956 R. L. PERL AUTOMATIC IGNITION UNIT FOR GAS BURNERS 2 Sheets-Sheet 2 Filed Nov. 20, 1950 flu. 7 3 MW 5 2 3 i 5 a w, w f m w a r 2,730,662 Patented Jan. 10, 1956 2,730,662 AUTOMATIC IGNITION UNIT non GAS BURNERS Richard'L. Perl, Gallon, Ohio, assignor to The Tappan Stove Company, Mansfield, Ohio, a corporation of Ohio Application November 20, 1950, Serial No. 196,683

3 Claims. (Cl. 317-83) This invention relates to automatic ignition mechanism for the top burners of cooking ranges using gaseous fuel.

It is expressly adapted for use with a plurality of spaced burners and includes a gaseous fuel pilot burner which is centrally disposed with respect to the main burners. The pilot burner is ignited by an electric resistance ignition element and the main burners are ignited by the pilot burner through flash tubes which extend from the main burners into close proximity with the pilot burner. The supply of gas to the pilot burner is controlled by the valves for the main burner. The opening of any of the main burner valves to supply gas to a main burner will also admit gas to the pilot burner. The electric ignition element is in an electric circuit which includes a normally closed switch and a plurality of normally open switches. There is a normally open switch operatively associated with each'burner valve in such a manner that the opening of the valve will close the switch, and conversely the closing of the valve will open the switch. The normallyclo'sed switchis arranged to be opened by a thermostaticelement which is mounted in position to be heated by the pilot burner after it has been ignited by the electric ignition element; The opening of the normally closed switch will breakthe circuit to and de-energize the electric ignition element which need not be energized after the pilot burner has been ignited. In operation it is only necessary to open the selected burner valve. The opening of the valve admits gas to the main burner and to the pilot burner and closes the normally open switch associated therewith. The closing of the normally open switch will make the circuit to and energize the electric Other and more limited objects of the invention will be apparent from the following specification and the accompanying drawings forming a part thereof wherein:

Fig. 1 is a diagrammatic layout showing my invention applied to a pair of spaced gaseous fuel burners;

Fig. 2 is an enlarged top plan view of the removable control unit;

Fig. 3 is a view similar to Fig. 2 showing the unit with electric ignition element and its carrier block removed to more clearly disclose certain of the parts thereof;

Fig. 4 is a central longitudinal section taken substantially on the line 44 of Fig. 2;

Fig. 5 is an enlarged section, taken on the line 5--5 of Fig. 1;

Fig. 6 is a transverse section, taken on the line 6--6 of Fig. 2;

Fig. 7 is a plan view of the thermostatic element; and

Fig. 8 is a side elevation of the thermostatic element as shown in Fig. 7.

The scale of Fig. 1 is approximately half size and Y the scale of Figs. 2 to 8, inclusive, is approximately full size.

Referring now to the drawings by reference characters, the numerals 1 and 2 are applied to a pair of spaced top burners of acooking range. Gaseous fuel is supplied to the burner 1, from a supply manifold 3, through its mixtween the free ends of a pair of aligned flash tubes 9 and 10 which are carried by the burners 1 and 2, respectively. Gaseous fuel is supplied to the pilot burner 3 from the manifold 3 through the valve 7 and the conduit 11 or through the valve 6 and the conduits 12 and 11. The

' cut-oil valves 6 and 7 are so constructed that when either resistance element which will then ignite the pilot burner.

The pilot burner will ignite the main burner through its flash tube, and will heat the thermostatic element, and the thermostatic element when heated will open the normally closed switch and break the circuit to and de-energize the electric resistance element. In the event the pilot burner should be extinguished for any reason while the gas is still turned on the thermostatic element will cool and close the normally closed switch which will re-energize the electric resistance element and re-ignite the pilot burner. i

This application is a modification of the devices shown in my co-pending applications, Serial No. 196,684, filed November 20, 1950, now Patent No. 2,693,517, Serial No. 196,682, filed November 20, 1950, now Patent No. 2,635,003, and Serial No. 196,681, filed November 20, 1950, now Patent No. 2,675,870.

The principal object of the invention is to provide a very simple and etficient automatic ignition mechanism for the top burners of cooking ranges.

Another object of the invention is to provide in a mechanism of this character, which includes a pilot burner and an electric resistance element which ignites the pilot burner, means operative to automatically de-energize the electric resistance element after the pilot burner has been ignited.

one is turned on to supply gas to one of the main burners 1 and 2 gas is also supplied to the pilot burner 8. The pilot burner 8 is ignited by an electric resistance ignition element 13 when it is energized, and the main burners 1 and 2 are ignited by the pilot burner 8 through the flash tubes 9 and 10. The electric ignition element 13 is mounted in operative relation to the pilot burner 8 on an insulating plug 14 of a removable control unit generally indicated by the numeral 15. The energization of the electric ignition element 13 is controlled by a pair of normally open switches 16 and 17 and a normally closed switch 18. The normally closed switch 16 is operatively associated with the valve 6 and comprises the contact 19 and 20 and the bridging conductor bar 21. The switch 16 is adapted to be closed through the medium of a cam section 22 carried by the valve stem 23 of the valve 6 and a link 24 simultaneously with the opening of the valve 6 and to be opened simultaneously with the closing of the valve 6. The normally open switch 17 is operatively associated with the valve 7 and comprises the contacts 25 and 26 and the bridging conductor bar 27. It is adapted to be closed through the medium of a cam section 23 carried by the valve stem 29 of the valve 7 and a link 30 simultaneously with the opening of tne valve 7 and to be opened simultaneously with the closing of the valve 7. The switch 18 is incorporated in the control unit 15 and is adapted to be opened by a thermostatic element 31 which is also incorporated in the control unit 15 in posi tion to be heated by the flame from the pilot burner 8. The specific construction of the control unit 15' and the component parts thereof will be described in detail hereinafter.

In operation it is only necessary to turn on the control valve of the selected main burner. The turning on or opening of the valve will close the associated normally open switch 16 or 17 and supply gas to both the main burner and the pilot burner. The closing of the switch 16 or 17 will make the circuit to and energize the electric ignition element 13 which will then ignite the pilot burner. The main burner will then be ignited through its flash tube by the pilot burner. After ignition the pilot burner will also heat the thermostatic element 31 which after being heated will open the normally closed switch 18 and maintain it open as long as the thermostatic element 31 is heated by the pilot burner. The opening of the normally closed switch 18 breaks the circuit to and de-energizes the electric ignition element 13 which need not remain energized after the pilot burner has been ignited. If after one main burner has been ignited the other main burner is turned on it will be ignited through its flash tube by the pilot burner which has already been ignited, it being understood that the pilot burner is arranged to burn as long as either of the main burners is turned on. If the pilot burner should be extinguished for any reason while either of the main burners is turned on, the thermostatic element 31 will immediately cool and allow the switch 18 to close which will reestablish the circuit to and re-energize the electric ignition element 13 which will then re-ignite the pilot burner 8.

The electric circuit which includes the electric ignition element 13, the normally open switches 16 and 17 and the normally closed valve 18 will now be traced, assuming first that the burner 1 is turned on by opening the valve 6. The opening of the valve 6 will supply gas to the main burner 1 and the pilot burner 8 and will close the normally open valve 16. As soon as the switch 16 is closed, current will flow from one side 32 of the line through the leads 33 and 34 to the contact 19 of the switch 16 and through the bar 21 to the contact 20. From the contact 20 the current will flow through the lead 35 to the terminal 36 of the electric resistance ignition element 13 and then through the ignition element 13 to the terminal 37 thereof. From the terminal 37 the cur rent will fiow through the switch 18 and back to the other side 39 of the line through the lead 40, completing the circuit to and energizing the ingition element 13, which will remain energized until the thermostatic element opens the switch 13 and breaks the circuit. Assume that the main burner 2 is first turned on by opening the valve 7. The opening of the valve 7 will supply gas to the main burner 2 and the pilot burner 8 and close the normally open switch 17. As soon as the switch 17 is closed, current will flow from the side 32 of the line through the lead 33, switch 17 and lead 41 to the lead 35. From the lead 35 the current will flow through the ignition element 13, switch 18 and back to the other side 39 of the line as previously described. The turning on of either one of the main burners after the other main burner has been turned on and ignited along with the pilot burner will not energize the electric ignition element 13 as the circuit thereto cannot be completed since the thermostatic element 31 is holding the switch 18 open.

The removable control unit 15 includes a frame, the electric ignition element 13 and the insulation plug 14, the normally closed switch 18, and the thermostatic element 31. The frame is formed of thin sheet metal and comprises a bottom wall 51 and a pair of spaced parallel upwardly extending vertical side walls 52 and 53 formed integrally therewith. It is removably secured to the underside of the top 54 of a range between the burners 1 and 2 by tabs 55 which extend outwardly from the upper edges of the side walls 52 and 53 into suitable pockets 56 carried by the range top 54. The bottom wall 51 has an opening 57 therethrough intermediate the ends thereof below which the pilot burner 8 and the ends of the flash tubes 9 and are disposed. The pilot burner 8 is held in proper position by a bracket 58 which is welded to the underside of the bottom wall 51 at 59, and has an arm 60 which extends upwardly through a slot 61 inthe wall 4 51. The upper end of the arm 60 is recessed as indicated at 62.

A socket 63, which comprises an inverted T-shaped block 64 of insulating material and the terminals 36 and 37, is secured to the wall 51 at one end thereof by a bolt 65. The vertical leg of the block 64 has a groove 66 cut in one side thereof under the terminal 36 and a similar groove 67 cut in the other side thereof under the terminal 37. The terminals 36 and 37 are held in place on the block 64 by bolts 68.

The plug 14 which is formed of insulating material carries a pair of spaced parallel conductors 70 and 71 which extend through the block and out beyond each end thereof. One projecting end of the conductor 70 is removably held by friction in the groove 66 in contact with the terminal 36 and the adjacent end of the conductor 71 is similarly held in the groove 67 in contact with the terminal 37. The end of the plug 14 opposite the socket 63 is supported in the recess 62 by the arm 60. The electrical resistance ignition element 13 is carried by and between the free ends of the conductors 70 and 71. above the opening 57 and the pilot burner 8 in position to ignite the pilot burner, as previously described. In case the ignition element 13 burns out, it is only necessary to withdraw the plug 14 and conductors carried thereby from the socket 63 and substitute a new plug.

The thermostatic element 31 is formed from a single piece of sheet metal and comprises a base 75 and a pair of spaced parallel narrow strips 76 and 77 which extend upwardly therefrom. The strip 76 is relatively long and extends a substantial distance on each side of the base 75, and the strip 77 is relatively short and extends only a short distance to one side of the base 75. The strip 76 terminates at one end thereof in a foot 78 which is disposed in the plane of the base 75, and the strip 77 terminates in a similar foot 79 close to the base 75 and on the same side thereof as the foot 78. The feet 78 and 79 are welded to the bottom wall 51 of the frame, the foot 78 being disposed on one side of the opening 57 and the foot 79 being disposed on the other side of the opening 57, so that the strip 76 extends across the opening 57 in position to be heated by the pilot burner 8.

The switch 18 comprises the stationary contact 80 and the movable contact 81. The stationary contact 80 is adjustably mounted in an extension 82 of the terminal 37 and the movable contact 81 is secured to the free end of the strip 76 of the thermostatic element 31. The switch 18 is normally closed with the contacts 80 and 81 in engagement with each other when the pilot burner is not burning. But after the pilot burner has been ignited by the ignition element 13 the flame from the pilot burner will impinge on and heat the strip 76 which will elongate it and cause the thermostatic element to flex about the midsection of the strip 77 and move the contact 81 out of engagement with the contact 80, thus opening the switch 18 and breaking the circuit to the electrical resistance ignition element 13.

From the foregoing it will be apparent to those skilled in this art that I have provided a very simple and eflicient mechanism for accomplishing the objects of the in vention.

It is to be understood that I am not limited to the specific construction shown and described herein as various modifications can be made therein within the spirit of the invention.

What is claimed is:

l. A thermally responsive switch comprising a frame having an opening therethrough, a normally closed switch having a stationary contact and a movable contact, and a thermostatic element carried by said frame; said thermostatic element being formed from a single piece of sheet metal and comprising a base having a relatively long strip and a relatively short strip extending upwardly therefrom in spaced relation to each other, said base and said short strip being disposed entirely on one side of said opening,

said short strip having one end thereof extending outwardly from said base toward said opening and said long strip having one end thereof extending outwardly from said base across said opening, the tips of said extending ends of said strips being rigidly secured to said frame on opposite sides of said opening; said stationary contact being secured to said frame and said movable contact being carried by the free end of said long strip in engagement with said stationary contact, said thermostatic element being operative when heated to move said movable contact out of engagement with said stationary contact.

2. A control unit for use in an automatic ignition mechanism for gaseous fuel burners, said control unit comprising a base, means carried by said base by which said unit is removably secured in operative position, an enlarged aperture through said base adjacent one end thereof, an electric socket having a pair of terminals secured to said base adjacent the other end thereof, a plug removably mounted in said socket and extending outwardly therefrom in spaced relation to said base, an electric resistance ignition element carried by the free end of said plug and disposed over said aperture, a thermostatic elernent carried by said base between said base and said plug and extending across said aperture, and a normally closed switch comprising a stationary contact connected to one of said terminals and a movable contact carried by said thermostatic element, said thermostatic element being operative when heated to open said normally closed switch.

3. A control unit for use in an automatic ignition mechanism for gaseous fuel burners, said control unit comprising a frame having a bottom wall and a pair of spaced upwardly extending side walls, means by which said unit is removably secured in operative position, an

enlarged opening through said bottom Wall adjacent one end of said frame, a socket having a pair of spaced terminals secured to the upper surface of said bottom wall adjacent the other end of said frame, in spaced relation to said opening, an elongated plug having a pair of spaced conductors which extend out beyond each end of said plug, one end of each of said conductors being removably secured in said socket with one of said conductors in engagement with one of said terminals and the other of said conductors in engagement with the other of said terminals, said plug being spaced from said bottom wall with the other end of each of said conductors being disposed over said opening, an electric resistance ignition element secured to and between the said other ends of said conductors, a thermostatic element carried by said bottom wall under said plug and extending across said opening, and a normally closed switch comprising a stationary contact carried by one of said terminals and a movable contact carried by said thermostatic element, said thermostatic element being operative when heated to open said normally closed switch.

References Cited in the file of this patent UNITED STATES PATENTS 370,801 McGowen Oct. 4, 1887 745,075 Kohn Mar. 8, 1904 886,100 Walker Apr. 28, 1908 1,026,848 Brown May 21, 1912 1,483,787 Dixon Feb. 12, 1924 2,192,632 Beam Mar. 5, 1940 2,221,667 Betz Nov. 12, 1940 2,296,686 Ragan Sept. 22, 1942 2,392,065 Rodgers Jan. 1, 1946 2,516,501 Altman July 25, 1950 

